Steam heating system



Filed March 25, 192% 2 Sheets-Sheet 1 EIIV'I INVENTOR. Jo/m' 5, ST/CKL E.

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Dec. 19, 1933. JJB. STICKLE STEAM HEATING SYSTEM 2 Sheets-Sheet 2 Filed March 2T5, 1929 1 m m m m Ja/m .8. 577cm:

BY r r ATTORNEYS.

Patented Dec. 19, 1933 UNITED STATES PATENT OFFICE p v STEAM HEATING SYSTEM John B. Stickle, Indianapolis, Ind. Application March 25, 1929. Serial No. 349,711

5 Claims.

atmospheric pressure. By reducing heating pressure considerably below atmospheric pressure when heating requirements are not severe, important savings in steam consumption may be made since the temperature of steam decreases rapidly with a decrease in absolute pressure and since the radiation from the heating surface is directly proportional to the temperature diifer ence between the steam therein and the room to be heated. For example, if the heating system of a building is designed, as is usually the case, to heat the building to '70 degrees Fahrenheit indoor temperature with five pounds per square inch of steam pressure above atmospheric'pressure, 228 degrees Fahrenheit steam temperature and zero degrees, Fahrenheit outdoor temperature, the

standard radiation computations show that the 7 building will be heated to the same indoor te'mperature with a steam pressure of twelve inches of vacuum, steam temperature 187 degrees Fahrenheit and an outdoor temperature of 18 degrees Fahrenheit-. Therefore, when the outdoor temperaturerises from zero degrees to 18 de-' grees Fahrenheit, the steam pressure may be;

reduced from five pounds above atmospheric to twelve inches mercury vacuum below atmospheric andthe steam temperature correspondin. response to the direction and velocity of the has usually been maintained by a vacuum pump running at a substantially constant speed independently of the heating pressure and heating requirements. The vacuum thus produced varies from day to day or hour to hour, depending 60 upon'the temperature of the condensate returned, the amount of condensate, the volume of air introduced therewith and other factors. Under these conditions, if the heating pressure is re- I duced to a point below atmospheric pressure too near to the return line vacuum, drainage from the radiators will be stopped and consequently all heating eiiect will cease. A stoppage of drainage can also be causedby an. accidental loss of vacuum due to failure of radiator traps, sudden increase of condensate, and other conditions. It is, therefore, necessary to run the vacuum pump at a speed to produce the highest-vacuum necessary 1 for the lowest expected heating pressure. Since the maintenance of a high vacuum requires an 7 increase in auxiliary power expense, this type of operation results in an unnecessary expense when heating pressures higher than the minimum are I being usedujff Certain features of the apparatus disclosed 0 herein arealso'discloseds and claimed in 00- pending application Serial No. 423,007, filed January 24,1930, which is a continuation in part hereof. w

Another. feature of the invention resides in 35,

the provision .of means for varying the pressure r-difierence between heating pressure and return line pressurefordifl'erent parts-of the building. 1 Another feature of the invention resides in 'thelprovision of means for controlling the heat-- ing pressure inresponse to wind velocity.

Another feature of the invention resides in the provision or means for controlling the heat.- ing pressure for difierent'parts of the building ingly reduced from 228 degreesFahrenheit 1871 ind degrees Fahrenheit. Under these conditions, a. saving of 26% in steam consumption may beniade with no decrease in heating comfort. When the,

than will be required on a still day. In the case {of large buildings particularly, a higher heating '1, pressure will be-required on the windward side fof' thebuildin'g than isrequired on the leeward IsideL; By means of certain features of the inoutdoor temperature rises higher thanfla de-.

grees Fahrenheit, increased economies maybe] made by reducing-the heating pressure, to; still lower absolute values.

To have any heating at all, there must be" a circulation, which means that with a high vacuv, In the case of buildings exposed to high winds, agiven indoor temperature will require greater heating pressure when a high wind is blowing vention hereinafter described, the heatingpresincreased when the wind velocity is above apredetermined point. By means of other features, the heating pressure on the windward side alone 01 a building may be similarly automatically in- 110.

creased, depending upon the direction of the wind.

Another feature of the invention resides in the provision of a time element by means of which sudden gusts of wind will not cause variation in heating pressure.

Other features of the invention and the full nature thereof will be understood from them:- companying drawings and the following specifications and claims:

Fig. 1 is a diagrammatic drawing of one form of apparatus comprising certain features of the invention. Fig. 2 is an electrical wiring diagram for a variation of apparatus which may be used. Fig. 3 illustrates apparatus responsive to wind conditions which may be used for controlling the pressure difl'erentials in different parts of the building. .Fig. 4 is an electrical wiring diagram for use with the apparatus of Fig. 3.

In the drawings a boiler 10 supplies live steam to a header 11 having branch mains 12 leading to difierent parts of a building. Included in each of the branch mains 12 there is a pressure-regulating valve 13. Leading from each of the valves 13 there is a heating main l4 supplying steam to a plurality of radiators v15. The condensate from the radiators 15 escapes through radiator traps 16 which are preferably of the type shownin Patent No. 1,570,714, issued to Cole Stickle January 26, 1926.

From the radiator traps the condensate is conducted from all parts of the building through a condensate return line 17 to a vacuum pump 20.

The vacuum pump is driven by a motor 21, withdraws the condensate from the condensate return line 17 and discharges it through a pipe line 22 back to the boiler. A suitable air trap 23 is attached to the pipe line 22 to permit the escape of air which may have leaked into the vacuum line.

Each of the regulating valves 13 is operated by a plunger 24 responsive to a diaphragm contained in the housing 25 to open and close the valve. A pipe line 26 connects the chamber above the diaphragm of each valve with the condensate return line 17. A pipe line 27 connects the chamber beneath the diaphragm of each valve with the corresponding heating main 14; Thus a pressure difference is maintained on the two sides of the diaphragm equal to the pressure diiference between the heating pressure and. return line vacuum. .This difierence of pressure is counterbalanced by means of a counterweight 28 carried on a lever 29 which is fulcrumed at 30 to a portion of the valve body and is attached to the plunger 24. By adjusting this counterweight the regulating valve may be made to maintain any pressure diiference desired.

-By using different valves for different parts of the building, the heating pressure may be made greater for one part than for another while the return line vacuum is the same for the several parts of the building 7 Several methods may be used for varying the return line vacuum and consequently the heating pressure. A preferred form is illustrated in Fig. 1 in which a second vacuum pump 31, driven by a motor 82, is arrangedin parallel with the pump 20. When a high vacuum is desired, both pumps 20 and 31 are operated. When a low vacuum is desired, piunp 31 is shut down. The, starting and stopping of pump 31 may be done manually or may be done under control of thermostats placed in suitable locations. A check valve 22a is placed in the pipe line 22 in the position shown in the drawings to prevent return flow of condensate through pump 31 when said pump is not in use. A similar check valve 10a prevents return flow from the boiler if both pumps are stopped.

In Fig. 1, the motor starter 83 for motor 82 is shown as controlled by thermostats 32 and 33 placed respectively outside and inside of the building. Thermostat 32 will be arranged to close its circuit when the outside temperature is above a predetermined figure, say 18 degrees Fahrenheit. The thermostat 33 will be set to close its circuit at some other predetermined temperature, usually about 70 degrees Fahrenheit. In order to operate the pump 31, it is necessary that the outdoor temperature be above 18 degrees and the indoor temperature be above 70 degrees.

In the example hereinbefore quoted herein the system will be adjusted so that a heating pressure of 5 pounds per square inch above atmosphere is maintained when pump 20 is operating alone and heating pressure of 12 inches of vacuum will be maintained when both pumps are operating. By the thermostatic arrangement shown, both pumps will operate only when outdoor temperature is above 18 degrees and indoor temperature is above 70 degrees. Thus, the high pressure steam will be available for rapidly heating the building to 70 degrees independently of the outside temperature. After the inside temperature has reached 70 degrees, the pressure is entirely under the control of the outside thermostat. Either of the thermostats 32 or 33 may be omitted and the control of the vacuum pump accomplished by either indoor or outdoor temperature acting alone.

With the apparatus just described, only one change of pressure is possible. Further increase of eificiency is obtained' when pressure is changed by several steps. This is possible when the vacuum pump 31' is omitted and the pump 20 is driven by a variable speed motor controlled by a plurality of thermostats as illustrated in Fig. 2. In this figure, thermostats 34, 35 and 36 may be adjusted to close their electrical circuits at successively increasing temperatures, for example at 10 degrees, 30 degrees and 50 degrees respectively. The electric circuits from these thermostats control a plurality of normally open relays 37 which are arranged to short circuit resistors 38 in the circuit of the shunt field 39 of the motor 21. By this arrangement the speed of the motor and consequently the speed of the vacuum pump is varied through successive steps, depending upon the temperature at the thermostats.

It is also possible to vary the speed of the pump by means of any common variable speed drive interposed between the pump and its driving motor and to control the ratio of said variable speed drive by the thermostats.

In Fig. 1 each of the valves 13 has associated therewith a solenoid 40 carried on a portion of the valve housing 41. The plunger 42 for each solenoid is supported on a spring 43 suspended from the end of the lever 29. When the solenoid is deenergized the spring and plunger hang as a dead weight on the lever 29 and serve as a portion of the counterweight necessary to produce the desired pressure differential. By energizing the solenoid its plunger is pulled down against the action of the spring and a force is exerted on the lever 29 depending upon the strength of the spring. By this means, a given pressure difference is maintained when the solenoid is deenergized and a larger pressure difference is maintained when the solenoid is energized. By suitably selecting the strength of the spring, the change in pressure differential may be made as great as desired.

Other means of varying the pressure differential may be used without departing from the spirit of the invention. For example, the weights 28 may be slidably mounted upon the lever 29 and adjustment secured by moving said weights under control of a suitable solenoid or motor.

Fig. 3 illustrates a form of electric apparatus responsive to the direction and velocity of wind and used to control the heating pressure for different parts of the building. A vertical shaft 44 is carried on a suitable step bearing 45 and a bearing 46 in the housing 47 and cover 48 respectively of a switch box. Said box may be located at a convenient position, preferably on the roof 49 of the building. A weather vane 50 is carried on the upper end of the shaft 44 and rotates the said shaft in response to changes in wind direction. Carried on the said shaft within the switch box is an arm 51 of insulation material carrying spring contact members 52 adapted to engage contact members 53, 54, 55, 56 and 57. The last-mentioned contact members are carried on an insulation piece 58 supported within the housing 47. The contact member 53 is circular in form and is always in contact with its corresponding member 52. Contacts 54, 55, 56 and 57 are arcuate in form as shown in Fig. 4 and are adapted to contact with their respective members 52 when the wind is from the east, west, north or south respectively.

A shaft 59 is carried on suitable bearings 60 and 61 in the housing 62 and the cover 63 respectively of a second switch box also mounted in a convenient position on the roof of the building. Carried on the upper end of the shaft 59 is a wind gauge wheel 64 of the general type'used by the United States Weather Bureau in measuring the velocity of the wind and adapted to rotate at a velocity proportional to said wind velocity. Carried on the shaft 59 within the housing is a usual type of fly-ball governor indicated generally by the numeral 65. Pivotally mounted within the housing is a bell crank 66 carrying on one arm a contact member 67 suitably insulated therefrom and adapted to contact with a second contact member 68 carried upon and suitably insulated from the housing 62. The opposite arm of the bellcrank 66 is associated with the movable member 69 of the fly-ball governor to close the contact between contact members 67 and 68 when the rotation of the fly-ball governor has reached a predetermined speed. By adjustment of the actuating spring 70 of the fly-ball governor, this contact may be made to occur at any desired wind velocity.

The electrical wiring for this control apparatus is shown in Fig. 4 wherein a pair of lines 71 lead from a suitable source of electric potential to the double pole knife switch 72. One pole of said switch is connected by line 73 to the contact member 68. The contact member 67 is con-,

nected by line 74 to the contact member 53. Contact members 52 are electrically connected to each other. Contact members 53, 54, 55 and 56 are connected respectively to solenoids 40E 40W, 408 and 40N. These solenoids correspond to the solenoids 40 in Fig.1 and operate to increase the pressure differential for the steam mains supplying the east, west, south and north sides of the building resptrtively. A common return line 78 leads from the opposite terminal of each of these solenoids to the contact member- 79 of a time relay switch. The opposite contactor 80 of the time relay switch is connected to the second pole of the knife switch 72. A solenoid 81 actuates the time relay switch and is connected by one terminal to the contact member 67 and by the opposite terminal to the contact member 80 of the time relay switch. This switch is of a common form wherein contact is made between contact members 79. and 80 only after solenoid 81 has been continuously actuated for a predetermined length of time.

By the operation of this circuit, the contact 6768 is made only when the wind velocity has reached a point which will cause a greater heating pressure to be required on the windward side upon the direction of the wind. Each of the arcuate contacts is connected to a corresponding pressure control solenoid and the circuit is completed through the common return line 78 to the knife switch 72 when the 79-80 contact is made as before described. By this method, a north wind, for example, blowing at a predetermined velocity fora predetermined length of time, will actuate solenoid 40N to raise the heating pressure on the north side of the building. Similarly, a west wind will raise the heating pressure on the west side of the building. By the overlapping of the arcuate contacts as shown in Fig. 4, a northwest wind will actuate both solenoids 40W and 40N to raise the heating pressure on both the north and west sides of the building.

In the case of small buildings or wherever it is desired to increase the heating pressure in the whole buliding when a high wind is blowing, regardless of the wind direction, the wind direction controller may be omitted and all of the solenoids may be operated directly from the wind velocity controller. In this case only one regulating valve 13 would be required for the entire building but as many could be used as convenient. The wind control apparatus herein shown may also be used independently of the particular form of apparatus herein described.

In these specifications and in the claims the terms heating pressure" and retum line vacuum" are used throughout but it is to be under-, stood that either or both of these pressures may be above or below atmospheric pressure. Where the word pressure is used without qualifications absolute pressur is understood.

The invention claimed is:

1. Steam heating apparatus including groups of heat radiating elements, a steam pipe for supplying steam to each of said groups, a common return line having a common vacuum throughout for removing condensate from all of said ele- 1 of said steam pipes whereby a difierent pressure may be maintained in each of said steam pipes.

2. A steam heating apparatus including a source of steam supply, a pressure regulating valve, a header supplying steam from said supply source to said pressure regulating valve, a plurality of heat radiating elements, a steam pipe conducting steam at reduced pressure from said regulating valve to said heat radiating elements, steam traps at the outlets of said elements, a. vacuum pump, a return line conducting condensate from said traps to said vacuum pump, a controller for operating said regulating valve in response to the difference in pressure between said steam pipe and said return line to maintain said pressure difference substantially at a predetermined value, a second vacuum pump in parallel relation with said first vacuum pump, and a thermostat controlling the operation of said second vacuum pump in response to temperature changes for varying the vacuum -in said return line and thereby varying the pressure in said steam pipe.

3. A steam heating apparatus including a source of steam supply, a plurality of pressure regulating valves, headers supplying steam from said supply source to said regulating valves, a plurality of groups of heat radiating elements, a steam pipe supplying steam from each of said regulating valves to one of said groups of heat radiating elements, steam traps at the outlets of said heating elements, a pump, a return line conducting condensate from said traps to said pump, controllers responsive to pressure differences between said steam pipes and said return line for operating said regulating valves to maintain said pressure difierences substantially at predetermined values, said controllers being adjustable to maintain a predetermined pressure difierence for each group of radiating elements independently of the others, and a wind responsive device for controlling said adjustment in response to wind direction.

4. A steam heating apparatus including a source of steam supply, a plurality of pressure regulating valves, headers supplying steam from said supply source to said regulating valves, a plurality of groups of heat radiating elements, a steam pipe supplying steam from each of said regulating valves to one of said groups of heat radiating elements, steam traps at the outlets of said elements, a pump, a return line conducting condensate from said traps to said pump, controllers responsive to pressure difference between said steam pipes and said return line for operating said regulating valves to maintain said pressure difi'erences substantially at predetermined values, said controllers being each adjustable to maintain a predetermined pressure diflference for each group of heat radiating elements independently of the others, and a windresponsive device for controlling said adjustment in response to wind direction and velocity.

5. Steam heating apparatus including heat radiating elements, a steam main for supplying steam to said elements, wind operated mechanism for increasing the pressure in said main in response to an increase in wind velocity and a time delay device operating to prevent said pressure increase until after said increased wind velocity has been maintained for a predetermined length of time.

JOHN B. BTICKLE. 

